Foundation & CMU Shell Construction for Builders
Licensed & Insured · CBC1267852 · Serving Tampa Bay
Footings, Slab, Block, Grout and Tie beam for New Builds, Additions and Commercial, from Layout to Lintel
Trusted by Tampa Bay Builders for Shells that Pass Inspection and Hold the Schedule.
Who we are
A Shell Contractor Built Around the GC's Schedule
Black Flag Contractors builds the concrete and masonry structure of the house, the part that has to be right before framing, roofing and every trade after it can start. We're a Florida Certified Building Contractor (CBC1267852) based in St. Petersburg. We work across Hillsborough, Pinellas, Pasco and Sarasota counties. Our job is simple: take your plans, build the shell to them, pass inspection, and hand the house back on schedule.
How We Work
One licensed contractor accountable for the whole shell, from layout to the last truss strap. You get one point of contact, not a different crew lead every phase.
What We're After
Builders who call us back for the next house. That comes from bids that match the plans, crews that show up, and inspections that pass the first time.
The Black Flag Way
Your Shell Sub from Bid to Final Strap
Every job starts with a full takeoff from your plans: footings, rebar, dowels, block, lintels, grout and tie beam, line by line. If the engineer calls out something specific, we price that product, not a generic stand-in, and tell you up front. Then we schedule, build and walk inspections so your framer isn’t waiting on us.
Trusted Company
Our Services
Concrete & Masonry Is All We Do
We don't frame, roof or finish interiors. We build foundations and CMU shells, and we build them to the plans.
Transforming Outdoor Spaces with Expert Care
Taking care of your property is our #1 priority when it comes to our work. Making sure that as much is protected and clear distance from our work
Eco-Friendly Practices for a Sustainable Future
Concrete is fully recyclable, and every concrete project we demo gets recycled
What We Build
Concrete and Masonry Services we Build
Shell Construction
Complete ground-up CMU shells: footings, slab, block, grout, rebar, lintels and tie beam, through truss straps. Inspections scheduled and walked by us.
Foundations and Slabs
Monolithic and stem-wall foundations, slabs on grade, thickened edges, pads and elevator pits, formed, reinforced and poured to plan.
Additions
Block additions tied into existing structures: demo, new footing and slab, dowels into existing, and CMU to match.
Elevated & Coastal Homes
Flood-zone builds with stem walls, engineered flood vents, elevator shafts and CMU below the design flood elevation, built to FEMA and FBC requirements.
Commercial
Light commercial foundations and CMU for new builds, additions, condos and site walls.
Stucco & Finish
Lath, stucco and texture over the block we built, so the shell leaves our hands ready for paint.
Premium Service
Plans In, Proposal Out in 24 Hours
Send a PDF plan set. Within 24 hours you get a line-item proposal broken into site prep, pre-pour, concrete and block shell, with every assumption and exclusion written down.
Why Choose Us
Why Builders Use Black Flag
Bids You Can Compare
Line items by phase, not one lump number.
Plan-driven Takeoffs
We price what the engineer specified, including named products, and flag anything missing from the set.
Inspections Handled
Footing, slab, cell and tie-beam inspections scheduled and walked.
One Accountable Contractor
A single licensed CBC managing every phase of the shell.
Coastal Experience
Flood zones, elevated slabs, flood vents and elevator shafts.
Testimonial
Client Feedback & Reviews
FAQ
Questions Builders Ask
Layout, footing excavation, forms, rebar and dowels, vapor barrier, slab pour, CMU walls, lintels, reinforced cells, grout, tie beam and truss straps set to plan.
A PDF plan set, including the foundation plan, wall sections and structural sheets. If sheets are missing, we list our assumptions in the proposal.
Usually within 24 hours of a complete plan set.
Yes. We schedule and walk footing, slab, cell and tie-beam inspections with the building department.
Yes. We can finish the shell with lath and stucco, or stop at the block for your stucco sub.
Email the plan set or upload it through the contact form. We'll confirm receipt the same day.
Hillsborough, Pinellas, Pasco and Sarasota counties.
Yes: stem-wall foundations, CMU below the design flood elevation, engineered flood vents and elevator pits.
Have a Set of Plans? Get a Shell Bid.
Builders across Tampa Bay use Black Flag for foundations and CMU shells that match the plans and hold the schedule.